fix(android/engine): Skip updating selection range if invalid

[darcywong00]

Fixes #11360

@mcdurdin went spelunking in the Android code and found getSelectionStart() and getSelectionEnd() return -1 if there's no selection or cursor. Reference https://developer.android.com/reference/android/text/Selection#getSelectionEnd(java.lang.CharSequence

In those cases (likely a race condition), we should no-op on updateSelectionRange() since there's no valid selection to pass to KeymanWeb.

User Testing (from #11360)

Setup - Install PR build of Keyman for Android and enable Keyman as the default system keyboard

• TEST_INVERTED_SELECTION_RANGE: Using Keyman for Android as a system keyboard, ensure that backwards selection ranges do not crash the keyboard.
  1. Select text, then drag one of the end points through and past the other one.
  2. If the keyboard immediately disappears, or you see an error notification, FAIL this test.

[keymanapp-test-bot[bot]]

User Test Results

Test specification and instructions

• ✅ TEST_INVERTED_SELECTION_RANGE (PASSED): I tested this issue with the attached "Keyman 17.0.320-beta-test-11384" build on an Android 14 environment: Here is my observation. (notes)

Test Artifacts

• Android
  • Keyman for Android apk
  • FirstVoices for Android 16.0 apk
  • FirstVoices Keyboards for Android apk
  • KeyboardHarness apk
  • Keyman for Android 16.0 apk
  • KMSample1 apk
  • KMSample2 apk

[dinakaranr]

Test Results

• TEST_INVERTED_SELECTION_RANGE (PASSED): I tested this issue with the attached "Keyman 17.0.320-beta-test-11384" build on an Android 14 environment: Here is my observation.
  1. Installed the "keyman-17.0.320.apk" file and gave all permissions to the application.
  2. Checked the "Enable Keyman as system-wide keyboard" and set the keyboard as the default keyboard box on the settings page. 
  3. Open the Chrome browser and then enter some text in the address bar.
  4. The keyboard did not disappear when selecting some text from right to left and left to right. The keyboard stays on the screen while dragging the text selection.

Note: The reverse text selection does not happen from one point to another. It's restricted to the last letter of the word. I observed this behavior in Android 13 (Physical Device) and emulator devices in Android 9 and 12 versions. However, it worked well, and I passed this test case. Thanks.

[keyman-server]

Changes in this pull request will be available for download in Keyman version 17.0.321-beta